Electric clock.



T. RUSHT ON.

ELECTRIC CLOCK. APPLICATION FILED APR. 18. 1914.

1,275,606. PatentedAug.13,1918.

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ELECTRIC CLOCK.

APPLICATION FILED APR. I8. 19m.

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Patented Aug. 13,- 1918.

T. RUSHTON. 'ELECTRIQ CLOCK. APPLICATION men APR. I8. I914.

1,275,606. Patented Aug. 13, 1911 4 SHEETS-SHEET 1.

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.THoMAs LBUSHTON, or TOLLINGT01\T 1?A RK, nonnon, nnGLANi),,AssIoNon T covnmfn? nnncmmc cLooK company LIMITED, or LONDON, ENGLAND;

nnno'rnrc CLOCK;

Specification of Letters Patent. Patent d A 13 1918 7 Application filed April 18, 1914. Serial 1% 832,966.

To all whom it may concern: H 1 Be itknown that I, THOMAS ,RUSHTON, a

, subject ofthe King of Great Britain, residing at 51 Birnam road, Tollington Park, in the county of London, England, have. in: vented new and useful Improvements in Electric Clocks, ofwhich the following is a specification.

This invention relates to electric clocks which are wound at intervals by an electro: magnet the circuit of which is automatically closed by the clock. i F

The invention comprises an electromagnetic driving andcontact mechanism including a longitudinally movable worm subjected to end pressure, adapted to rotate the clock train and itself to be rotated by electromagnetic means, and controlling by its longitudinal movement the electric circuit of the apparatus.

The invention further includes an improved electrical contactfor suchelectromagnetic driving mechanism, one portion of which is constituted by a rotatable arbor which revolves while making contact with a non-rotary member. r i

The" invention consists also in a clock maintained in motion by endwise pressure on a worm engaging the clock train, thesaid worm being traversed longitudinally at intervals against such endwise pressure as the result of rotation efiected byelectromagnetic means the circuit of which is controlled by the longitudinal movement of the worm. p 3* Constructions according 'to'the invention are illustrated in the accompanying drawings in which Figure 1 shows the electromagnetic winding and. contact apparatus assumed to be winding the ordinary driving spring (not shown) of a clock train.

Figs. 2 and 3 are details of alternatlve constructions. I

Figs. 4, 5 and 6 .areside and end elevations respectively of an electromagnetlcally driven clock which has no driving spring other than that bearing on the worm shaft.

Fig. 7 is a detail of a contact mechanism of this clock.

In the arrangement of 1 a spur wheel Lon-the spring drum. (not shown) is rotated for winding purposes by means of a p nion 2 on the shaft 3. This latter carrles a worm; wheel {1 meshing with the worm 5, the shaft 6 of which bears a ratchet wheel 7 adaptedto be rotated by the electromagnetic winding device. .The shaft 6,.isjmovable longitudinally 'in bearings. The ten-' sion of the Idrivingspring action through the gearing 1, 2, 3, 4:, 5 tends to move it in one j'dlrection, and a leaf or, other spring 8 bearing on one end of it counteracts this pressure. The opposite end of thehshaft 6 1s cut into facets 9 so as to present'grinding edges and bears against a silver or like facing 10 upon an adjustable terminal block 1.1 which is mounted on but insulated from the, frame of the clock. This block is joined by ,a conductor-l2 to one pole of a suitable battery 30 or other source of supply.

The electromagnetic winding device by which the spring 8 is restored to its initial position, after it has caused the closing of the circuit may be of theform shown in Fig. 1. This comprises an electromagnet 13 the armature 1 1 of whichecarries a hammer 15 to regulate its rate of vibration. It also bears a contact spring 16, which, when thearmatureisnot attracted, rests against a contact screw 17 which is joined by a conductor 18 to one terminal of the magnet winding, the remaining terminal being connected by the lead 19 to theother pole of the battery or other source of power. The terminal screw 17 is insulated from the clock frame. Thus the complete circuit ofthe electromagnetic device is as follows: from p the battery by lead 12, through terminal 11, contact '10, shaft 6: of the worm, the frame of the clock, the armature 14, the spring 16, thecontact 17, lead 18, the windings of the electromagnet, and lead 19 to the battery. WVhen the armature is attracted, contact is broken between 16 and 17, with the result that the armature is at once released and moves back to the position shown under the action of spring 20. Pivoted upon the armature 14 is a spring-pressed pawl 21which engages the ratchet teeth7. Thus asthe armature oscillates it rotates the shaft 6. If

. position shown in the drawing.

spring lessens the spring 8 is able to press down the shaft 6 thus virtually winding the clock a very little without rotationof the worm. The result of this is finally to bring about contact between 9 and 10, thus closing the circuit above described. The armature 14 then vibrates, rotating the shaft 6 as it recedes from its attracted position and through the gearing winding the driving spring. This continues until the tension of the spring is sufliciently increased to cause theworm shaft 6 to be moved again against the action of spring 8 to break contact.

It is not necessary that the operating contact should be actually made by the shaft 6. An alternative construction is illustrated diagrammatically in Fig. 2. There, 22 rep resents a snail cam upon the shaft 6, the circumference of which is approximately circular throughout the greater part of its circumference. This forms one of the contact members. The other is a spring or springpressed' arm 23 notched at 24. Normally this arm rests upon the edge of a spring 25 which corresponds with the spring 8 bearing upon the end of the shaft 6.

hen the shaft yields owing to the lessening of tension of the driving spring, the movement of spring 25 brings it opposite the notch 24', with the result that the arm 23 falls. It thus makes contact with the cam 22 completing the winding circuit. In winding, the cam 22 is rotated and lifts the arm 23 to such a position that the spring 25 can rengage with it. Such reengagement will take place when the driving spring is sufficiently tensioned to overcomethe spring 25. After this has occurred the further rotation of the cam 22 will break the circuit because the arm 23 will not fall when it comes to the step of the cam. I

Yet another arrangement of the contacts is shown diagrammatically in Fig. 3 where 26 represents a snail cam upon the shaft 3 or other'shaft driven therefrom. Upon this cam rests the insulating end 27 of a contact spring 28. A second contact spring 29 is pressed against the spring 28 except in the In this position the-end of the spring 29 is upheld by the step of the cam for a short interval after-the spring 28 has fallen.

which is prior to the release of spring 29,

breaks the circuit.

It will be apparent from the above description that the worm effects some portion of the winding of the main spring by its longitudinal motion under the action of spring 8'. Where there is a drivingspring of the ordinary form this portion of the winding is smallcompared with that which is effected by the rotation ofthe worm. But if a stiff driving spring is employed a comparatively small amount of winding: of the spring will correspond with the normal range of displacement of spring 8, and the longitudinal motion of the worm wi-ll account for a larger proportion of the total amount of winding. The stiffer the driving spring the less will be the rotation of pinion 4 during the vibration of the armature. If the ordinary driving spring be altogether omitted, that is the same as making it infinitely stiffer. Spring 8 is then the only driving spring in the clock and the drive of the clock is brought about by the longitudinal motion of the shaft 6. The rotation of the shaft-by the electromagnet does not cause any substantial rotation of the wheel 4 but rather causes the worm to screw past the wheel and displace thespring 8. The construction. .of Figs. 4-7is designed to work in this fashion. In the arrangement of these figures, the operating electromagnet is indi cated at 31-. Its armature 32 is pivoted at 33 and is normally pressed into una-ttracted position by the-spring 34 the tension of which may be adjusted by a screw 35. The prolongation of spring 34 forms also the back contact 36 ofthe armature, which, when the armature is unattracted,. rests against adjustable screw 37. At its free end the armature carries aleaf spring. 38 forming a pawl which engages with a fine milled ratchet wheel 39 secured on a worm shaft 40 carrying at 41 a worm which engages the first wheel 42 of the clock train. The wormwheel 42 has a wheel 50 on its arbor meshing with a pinion 51 on the same arbor as a wheel 52, which in its turn drives the pinion 53. The last wheel 43 of the clock train is a crown wheel on the arbor of pinion l forms a contact-it preferably being somewhat pointed and formed with facets which can abut upon the fixedcontact 45.

The method of operation of this apparatus is closely analogous to that of the clock first above described. But now the spring 44 is the only spring of the clock. The armature 32 when attracted breaks its back contact 36, and proceeding further under its own momentum takes up a tooth of the ratchet wheel 39. In returning under the action of it spring 34 it rotates the ratchet wheel 39 and screws the worm 41 past the wheel 42, pressing back the spring 44 and also breaking contact between the shaft and the contact 45. The spring 44 drives the clock train through the worm 41 acting as a rack until contact is again made in the worm spindle and contact 45. Winding then again takes place, the armature 32 making a single vibration and breaking the contact between the worm spindle and contact 45 before it re-makes its back contact 36.

It will be apparent that the spring 44 could readily be replaced by a weight bearing directly or indirectly upon the spindle so as to press it endwise. Such a construction would be useful in connection with turret and other large and exposed clocks.

What I claim is:

1. In an electric clock the combination of a train of wheels, a worm engaging one member of said train and formed at one end as an electrical contact, a fixed contact serving as an abutment for the contact end of said worm, a spring pressing said worm longitudinally to close said contacts and electro-magnetic means for rotating said worm in order to wind the clock, and conducting means for electricity including a source of electricity from the contact to the electro magnetic means.

2. In an electric clock the combination of a train of wheels, a worm engaging with one member of said train, an electro-magnet for rotating said worm in step-by-step fashion, a fixed contact serving as an abutment for one end of said worm and a spring pressing upon the other end of said worm to close said contact and to drive said train, and of such dimensions as to be fully stressed by a single stroke of said electromagnet, and conducting means for electricity including a source of electricity from the contact to the electro magnetic means.

3. In an electric clock, the combination of a train of .wheels, a worm engaging one member of said train, electro-magnetic means for rotating said worm to wind the clock, an electrical contact in the circuit of said electro-magnetic means operated by longitudinal motion of said worm, and a spring pressing upon one end of said worm,

adapted both to control said electrical contact and to serve as thedriving spring for said train, and conducting means for electricity including a source of electricity from the contact to the electro magnetic means.

4. In an electric clock the combination of a train of wheels, a worm engaging one member of said train, and formed at one end as an electrical contact, electromagnetic means for rotating said worm in order to wind the clock, a fixed contact in the circuit of said means serving as an abut ment for the contact end of said worm, a spring pressing said worm longitudinally to bring said contact members into contact, in order to close the circuit of said electromagnetic means, and a further contact in said circuit in operative connection with said electro-magnetic means for opening the circuit of the latter, and conducting means for electricity including a source of electricity from the contact to the electro magnetic means.

5. In an electric clock the combination of a train of wheels, a worm engaging one member of said train and formed at one end as an electrical contact, electro-magnetic means for rotating said worm in order to wind the clock including a ratchet wheel in the worm, a pawl engaging the ratchet wheel, and an armature of an electro-magnet carrying the pawl, a fixed contact in the circuit of said means serving as an abutment for the contact end of said worm, a spring pressing said worm longitudinally to bring said contact members into contact, in order to close the circuit of said electro-magnetic means, and a further contact in said circuit in operative connection with said electromagnetic means for opening the circuit of the latter.

6. In an electric clock the combination of a train of wheels, a worm engaging with one member of said train, an electro-magnet for rotating said worm in step by step fashion, including a ratchet wheel on the worm, a pawl engaging the worm and an armature of the electro-magnetic means carrying the pawl, a fixed contact serving as an abutment for one end of said worm and a spring pressing upon the other end of said worm to close said contact and to drive said train, and of such dimensions as to be fully stressed by a single stroke of said electro-magnet.

In testimony whereof I have signed my name to this specification in the presence of two subscrlbing witnesses.

THOMAS RUSHTON.

Witnesses:

A. E. ODELL, LEONARD E. HAYNES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatentl.

' Washington, D. 0. 

